The present invention relates in general to a stalk-type lever switch for mounting to an automotive steering column, and, more specifically, to a stalk switch with provision for separately controlling wiper on/off/intermittent settings, an intermittent delay setting, and a washer spray function.
Stalk-type lever controls mounted to an automotive steering column for controlling windshield wiper and washer functions have become well accepted in the automotive industry. Various arrangements have been conceived for controlling multiple functions. These typically use various electrical switches and sliding contacts at the base and in the head of the stalk. Functions that may be controlled include wiper motor on continuous, wiper motor on intermittent, intermittent wiper delay setting, washer spray on, headlights and/or running lights on/off, high beam headlights on/off, turn signal lights on/off, etc.
In order to be successful, a stalk-type lever control should be robust, durable, and inexpensive to manufacture. To achieve the multiple control actions, however, the lever controls have become complicated. A lever often combines several different control action movements including axial rotation, circumferential rotation, and longitudinal displacement. Axial rotation may typically include either pivoting in a plane perpendicular to the axis of the steering column (as is sometimes used for controlling windshield wipers) or pivoting in a plane parallel with the axis of the steering column (as is sometimes used for controlling headlamp high beams). Circumferential rotation includes pivoting a ring around the longitudinal axis of the lever (as is used for controlling intermittent wiper delay). Longitudinal displacement may include a push button at the tip of the lever (as is sometimes used for controlling windshield washers). Combining these actions in a single structure has continued to be a challenge.
Robustness of a structure includes the ability to withstand forces applied in directions other than those being used for control actions. For example, a lever designed to pivot in only one plane (e.g., perpendicular to the axis of the steering column) must not malfunction if the lever is pushed in a direction outside that plane (e.g., in a direction parallel to the axis of the steering column).
The present invention provides an improved structure for a multifunction stalk-mounted switch having the advantages of robustness, durability, and ease of manufacture.
In one aspect, the multifunction switch apparatus comprises a lever including a lever arm having a distal end for manually manipulating the switch apparatus, a control frame at a proximal end of the lever, and a longitudinal bore. A case pivotally retains the control frame for movement in a pivot plane defined by a pivot axis. A circuit board is mounted in the case and comprises circuit traces on a surface thereof. A first contact is mounted to the control frame and slidably contacts the circuit traces. A rod is movably retained in the longitudinal bore and has a proximal end and a distal end. The rod includes a radial control arm and a drive surface at the proximal end. A contact carrier is rotatably mounted within the control frame and is coupled to the radial control arm so that the contact carrier rotates in response to axial rotation of the rod. A second contact is mounted to the contact carrier and slidably contacts the circuit traces. A plunger is biased in a first position and has a cam surface for receiving the drive surface and moves into a second position in response to longitudinal movement of the rod. The plunger includes an actuator surface. An on/off contact switch is mounted to the circuit board and makes selectable contact in response to the actuator surface.